1. Field of the Invention
This invention is concerned with a self-propelled vehicle engine cooling system. More particularly the invention relates to utilization of separate chambers for enclosing the engine and various heat exchangers. Each compartment is evacuated by a fan directing air flow to an air discharge opening between the separate engine and heat exchanger chambers.
2. Description of the Prior Art
Almost since the advent of water cooled motor vehicles the radiator and engine layout has been relatively consistent with the radiator or heat exchanger at the front end of the vehicle and the engine located between the heat exchanger and the passenger compartment. Of course there have been many alternative layouts, especially in early vehicles and buses, but in general and particularly in the working machine, i.e., tractor art, the layout has been conventional.
In this age of environmental enlightenment, industry sees the need to provide quiet running machines both for compliance with "noise pollution" regulations and to offer the customer the benefit of a quiet machine. Early developments were simple endeavors where technicians would position noise barriers around sources of noise--typically the vehicle engine compartment including the heat exchanger fan. Of course noise was thereby controlled to a degree but engine compartment cooling emerged as a problem due to restricted air flow around the engine.
A solution to the noise and cooling problem is presented in U.S. Pat. No. 4,086,976 entitled "Isolated Clean Air Chamber and Engine Compartment in a Tractor Vehicle," wherein an enclosed engine compartment is plumbed to an evacuation duct and engine heated air is blown out the front of the tractor vehicle. A single fan also pulls air through the radiator and pushes it out the grille opening. Although this embodiment represents a departure from more conventional/heat exchanger layouts it is significantly different from the instant invention as the instant invention incorporates two separate chambers, one for the engine and the second for the coolant heat exchangers as well as two fans providing flow from respective chambers to a centrally located discharge opening.
One advantage of this invention over the prior art is that the device provides for a sound insulated engine compartment that is segregated from the vehicle's heat exchangers and is evacuated through the use of a small fan, in conjunction with a sound insulated heat exchanger compartment evacuated by a large fan such that both fan noise and engine temperature are controlled.
An object of the invention is to provide for engine compartment air flow sufficient to minimize heat build up in the engine compartment.
Another object of the invention is to provide for a sound insulated heat exchanger compartment that allows sufficient air flow through the heat exchangers while minimizing the measured noise pressure level at the front of the tractor.
Also an object of the invention is to provide a central air discharge port located between the engine and the vehicle's heat exchanger where air from both the small fan and the large heat exchanger fan can be comingled and forcably exhausted in a general radial pattern.
Another object of the invention is to allow the almost complete enclosure of the engine compartment except for judiciously placed openings required to supply air to the engine compartment.
Also an advantage of this invention is that the engine compartment resident components are not subjected to the high velocity stream of air borne debris usually associated with a conventional fan. Therefore the engine compartment and the engine may stay cleaner and drier than would contemporary conventional engine compartment layouts.